ACCUMULATED OTHER COMPREHENSIVE INCOME, After Tax Changes in Each Component (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2015	Mar. 31, 2014
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated other comprehensive income (loss) as of the beginning of the period	$ (8,352)	$ 5,545	$ (1,888)	$ 10,726
Other comprehensive income (loss) before reclassifications and taxes	1,761	2,977	1,997	8,229
Amounts reclassified from accumulated other comprehensive loss, before tax	58	(39)	58	(3,731)
Pre-tax net other comprehensive income (loss)	1,819	2,938	2,055	4,498
Income tax effect	(16,262)	(9,717)	(22,962)	(16,458)
Net other comprehensive income (loss) for the period, net of tax	(14,443)	(6,779)	(20,907)	(11,960)
Accumulated other comprehensive income (loss) as of the end of the period	(22,795)	(1,234)	(22,795)	(1,234)
Unrealized gain (loss) on available for sale securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated other comprehensive income (loss) as of the beginning of the period	4,721	(182)	4,745	(1,276)
Other comprehensive income (loss) before reclassifications and taxes	3,801	5,668	3,745	11,127
Amounts reclassified from accumulated other comprehensive loss, before tax	(2)	(39)	(2)	(3,731)
Pre-tax net other comprehensive income (loss)	3,799	5,629	3,743	7,396
Income tax effect	(1,462)	(2,147)	(1,430)	(2,820)
Net other comprehensive income (loss) for the period, net of tax	2,337	3,482	2,313	4,576
Accumulated other comprehensive income (loss) as of the end of the period	7,058	3,300	7,058	3,300
Net currency translations and net investment hedges
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated other comprehensive income (loss) as of the beginning of the period	(13,073)	5,727	(6,633)	12,002
Other comprehensive income (loss) before reclassifications and taxes	441	(2,691)	733	(2,898)
Amounts reclassified from accumulated other comprehensive loss, before tax	0	0	0	0
Pre-tax net other comprehensive income (loss)	441	(2,691)	733	(2,898)
Income tax effect	(15,720)	(7,570)	(22,452)	(13,638)
Net other comprehensive income (loss) for the period, net of tax	(15,279)	(10,261)	(21,719)	(16,536)
Accumulated other comprehensive income (loss) as of the end of the period	(28,352)	(4,534)	(28,352)	(4,534)
Cash flow hedge
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated other comprehensive income (loss) as of the beginning of the period	0	0	0	0
Other comprehensive income (loss) before reclassifications and taxes	(2,481)	0	(2,481)	0
Amounts reclassified from accumulated other comprehensive loss, before tax	60	0	60	0
Pre-tax net other comprehensive income (loss)	(2,421)	0	(2,421)	0
Income tax effect	920	0	920	0
Net other comprehensive income (loss) for the period, net of tax	(1,501)	0	(1,501)	0
Accumulated other comprehensive income (loss) as of the end of the period	$ (1,501)	$ 0	$ (1,501)	$ 0